@Astuart.mcpherson1710,
As shown in this Sonos support link below:

https://support.sonos.com/en-us/article/sonos-s2-compatibility

1. The Arc & Roam, as listed in your community profile are S2 only
2. The Play:1 & 3 are both S1 & S2 compatible
3. The Play:5 (gen1) is S1 only.

I would separate those listed in 2 above, however you choose, it’s your preference.

Perhaps use both within the same Sonos account (optional), but just ensure each system uses an entirely separate Sonos HouseholdID, otherwise the link between each system will continue to exist. It’s best you keep them separate and then you will not face the dilemma that you mention, of your S1 controller App referring to Sonos 2.

Hope that assists.

Thank you for your advice …..much appreciated